For me, this years winter building season has begun. I have always wanted a 1/12 scale Douglas Dauntless dive bomber. I know there is an ARF kit available from Windrider, but I like to scratch build my own designs.

I am intending on designing alternate wings for the SnickerSnee fuselage structure, a 1.5m powered glider wing and an aileron trainer wing. The idea is to have a platform that can grow with the pilot. Beginning pilots can start with the 3 channel Powered Glider wing to help them get used to orientation. Advance to training with ailerons and ultimately work with the aerobatic combat version. I scratch built this wing to use for powered glider testing. Overall I'm happy with the performance.

I took it out to the field a few days ago and let my Pops fly it. Asked him, "you like it?" He had a grin on his face, "yup." Asked him, "you want it?". Again, "yup." He has since put one of those gyro stabilizers into it. Has no problems landing on our runway in a cross wind. Fun plane.

Back in the day, my dad designed a slow-combat control line that he called the Snickersnee. In his honor I want to design, laser cut, and build a 400 sized electric stick for r/c streamer combat.

Pops original Snickersnee design was characterized by its diamond shaped wing tips and sharp corners. The slow-combat control line model looked very similar to this model I set up for the RealFlight simulator a while back:

My design process usually starts by drafting a simple scale drawing to import into 3DS Max so I can generate a 3D model for design testing in RealFlight. Once I'm happy with the shape and size of the flight surfaces and the handling in the sim I start designing the structure.

Usually my design process includes building a model for RealFlight to test things like airfoils, wing incidence, dihedral, thrust angles, control surface size, etc. Once I'm happy with the flight characteristics in the simulator I can start designing and fitting the actual parts in 3DS. From there I can extract the parts out to AutoCad to lay out plans and set up templates to lay out on balsa and light ply or to set up G-Code for laser cutting.

This project will be a park sized sport plane with the classic lines of the AstroHog. I'm shooting for a 40" wingspan aircraft with a flying weight between 20 and 24 ounces. Should be able to power it with a 400-480 sized outrunner.

So far, I've got the model for RealFlight is completed and I like the way it flies. At this weight and wing area the flaps are really not needed, but they are fun. I've opted for slightly over-sized wheels for ground handling in grass.

Just got this one mostly finished. Did several mods including rebuilding the wing saddle to fix the incidence, firewall mounted a 400 sized outrunner, built new landing gear pads, carbon fiber spar, glassed the inside of the fuselage to reinforce the wing saddle area (and slightly aft), bent new tail wheel wire, covered with light silkspan/WBPU.

I didn't like the idea of simply using velcro to attach the canopy so I modified that area and made the cockpit removeable to access the battery. Can get the lipo all the way up to the firewall easily.

My final flying weight came out at 15.8 ounces with the CoG right at 57mm with the battery all the way forward. I'm going to try the stock landing gear wire for the maiden flight, but I'm afraid it's a bit too wimpy. Will give the stock gear a shot before making gear doors. I'm thinking I will have to bend new gear from 3/32" music wire like most of my other GWS warbirds.

Images

Here's some build photos of my newest GWS bird. This one will have flaps, retracts and ailerons without exposed control horns. A three servo wing. I plan to keep it as light as possible, but after hogging all of the foam out near the root of the wing for the retracts and the extra servos I'm afraid the wing will fold. I've added a carbon fiber spar and plan on fiberglassing the wing root to help strengthen it back up.

I decided to add a short length of bamboo to the tips to keep them from snapping off during the first less than perfect landing. I used the Kavan Secret Hinges in the ailerons and customized the stock torque rods to drive the flaps. Again, I added a bit of 1/16" light ply to mount the Kavan hinges to get the strength back where I had to hog the foam out of the wing. I dropped the torque rods in from the top of the wing so the flaps will hinge at the top surface instead of the middle.

This is what I've got done so far. Wing weight at this point is around 4 ounces with all the hardware. I am planning on finishing this plane with ParkLite covering.

I used the windex trick to remove the paper from the board and then re-covered it with ParkLite (Ultracote). No need for carbon spars with the covering and it doesn't add a whole lot of weight. Weighs about half what the paper does and more than doubles the original strength. In my opinion it's worth the bit of extra weight for the extra strength and rigidity.

I ended up using a Rimfire 370 with a 9x6SF prop. ESC is a Thunderbird 18. I will be flying it with 1000-1320 mah 3S Lipos. Comes out to about 110 watts static on the meter. I used transparent black spray to smoke the canopy. I like the effect. Hopefully I will get a chance to maiden this weekend. It's covered with white and red ParkLite. I still need to open up a hole in the scoop underside of the cowling. Final AUW is 14.8 ounces with the wheel pants and 1000mah 30C 3S lipo.

As usual fairly gusty winds that night. Landing was a bit rough, but nothing broke. Had a nice head wind with flaps down for the landing approach that turned into a side wind that blew the plane off the runway and then stopped altogether causing the plane to fall from a couple feet up. No damage.

Images

Here's a video of my scratch built AmpMaster clone. Winds were fairly strong as usual this time of the year. I'm guessing 15-20 mph based on the Beaufort Scale. I have the plane balanced a bit nose heavy to handle the winds and for a bit of aerobatics. On calm days I move the battery back an inch or two to practice 3D stuff. Really is a nice flying, versatile plane.